Presently various fluids are used for heat transfer. The suitability of the heat transfer fluid depends upon the application process. For example, some electronic applications require a heat transfer fluid that is inert, has a high dielectric strength, has low toxicity, has good environmental properties, and has good heat transfer properties over a wide temperature range. Other applications require precise temperature control and thus the heat transfer fluid is required to be a single phase over the entire process temperature range and the heat transfer fluid properties are required to be predictable, i.e., the composition remains relatively constant so that the viscosity, boiling point, etc., can be predicted so that a precise temperature can be maintained and so that the equipment can be appropriately designed.
In the semiconductor industry, there are numerous devices or processes that require a heat transfer fluid having select properties. These include testing the performance of semiconductor wafer chips, controlling temperature during reactive plasma etching, producing steppers, operating ashers, operating plasma enhanced chemical vapor deposition (PECVD) chambers, conducting thermal shock tests, and for constant temperature baths. The heat transfer fluid may be used to remove heat, add heat, or maintain a temperature.